How to iterate hashmap in reverse order in Java

Question

I am trying this for some hour but not finding any best approach to achieve iteration of hashmap in reverse order, this is the hashmap I have.

      Map

        

Answer 1

You can use TreeMap#descendingKeySet method.

Map> map = new TreeMap>();

for(Integer key : map.descendingKeySet()) {
    List value = map.get(key);
    List> security = new LinkedList>();  
    for(int ixy = 0; ixy < value.size()-1; ixy++){
        security.add(createItem(value.get(ixy), value.get(ixy+1))); 
    }
    adapter.addSection(Integer.toString(key), new SimpleAdapter(getApplicationContext(), security, R.layout.list_complex, new String[] { ITEM_TITLE, ITEM_CAPTION }, new int[] { R.id.list_complex_title, R.id.list_complex_caption }));
} 

Reference:

https://docs.oracle.com/javase/8/docs/api/java/util/TreeMap.html#descendingKeySet--